What molecules are involved in nuclear fission? and what does it create

Nuclear fission is the splitting of an atom's nucleus to create nuclei of lighter atoms (smaller nuclei), accompanied by a release of large amounts of energy. for instance, when the massive  uranium atom is hit by neutron, this can result in splitting of nucleus to form nuclei of atoms of rb and cs. particles present in the nucleus participate in nuclear fission

What formula  this one  (x_/